In an episode of The Tyra Banks Show that aired Tuesday, Banks surprised 22-year-old Isis King with Dr. Marci Bowers, who offered to evaluate Isis and perform the surgery.

"This is not happening," Isis said, adding that she felt "like I'm about to wake up."

Bowers, who has undergone the procedure herself and is the star of a new reality series, Sex Change Hospital on We tv, told TVGuide.com the surgery will take place early next year.

The season finale of Top Model airs Wednesday. Isis, who was born Darrell Walls and has described herself as "a woman born physically male," was the fifth contestant to be sent home from the show.

She told Banks on Tuesday's show that she felt uncomfortable taking photos in a pool because she had not yet undergone surgery. She was sent home after the photos. She was living in a Maryland homeless shelter before she appeared on Top Model.

"When transgendered characters appear on major TV networks, and of course when she made her appearance on the America's Next Top Model show, it caught my attention," Bowers said. "And then Tyra contacted us and we sort of came up with this idea: Why don't we help her out? She's a struggling model, and lovely."Bowers said she and Banks are sharing the costs of the surgery, which comes in at less than $20,000.Bowers, an obstetrician-gynecologist for 22 years, said she has performed the surgery about 600 times.About one in every 2000 to 3000 people are transgendered, Bowers said — about the same as the number of people who are born with cleft palates."If you know somebody who's had a cleft palate, then you probably know somebody... who is transgendered," Bowers said.The relative simplicity of the 3½-hour procedure illustrates the physical similarities between men and women, she added.Certain organs become either male or female during fetal development. In the surgery, called vaginaplasty, male organs are changed into their female counterparts."The testicles are removed," Bowers said. "That's about the only thing that's discarded."Isis did not return a message left with Bowers.